Arch bridge installed in Mumbai coastal road project

Freight Wings Pvt. Ltd. successfully installed a 2500 Tonnes Arch Bridge with dimensions of 143.3 x 31.8 x 31.27 as part of the Mumbai Coastal Road Package 2 project, demonstrating their engineering prowess.

The HCC-HDC JV is carrying out the Mumbai Coastal Road Package 2 project, which called for the fabrication and installation of six composite spans measuring 60 x 29 x 2.95 metres and weighing 350 to 600 metric tonnes, as well as two arch spans of unprecedented dimensions measuring 143.3 x 31.8 x 31.27 metres and weighing 2000 and 2400 metric tonnes, respectively.

Freight Wings Pvt. Ltd. was faced with the daunting task of lifting, transporting, and installing these massive structures, deciding on the float-over method due to the shallow draft and predicted weather conditions, which included high wave heights of up to 1.5 metres.

To carry out this complex operation, Freight Wings used a fleet of 250-class barges with tugs, 120 self-propelled modular transporters (SPMTs), 32 strand jacks with capacities ranging from 200 to 980 metric tonnes each, quick-lowering long-stroke tidal jacks with capacities of 5000 metric tonnes, heavy-duty tower modules, mooring winches, rapid ballast systems, and leg mating units.

Preparations for the installation began in January 2024, with the first composite span successfully placed on February 1st, followed by three more on March 26th. However, as weather conditions deteriorated, particularly in April, innovative alterations were made to the technical design, including the implementation of a two-body system and the deployment of a 110 x 64 x 6-metre barge weighing 25,000 DWT to assure operational safety.

The first arch span was carried onto the barge on April 14th and sailed to the installation site on April 24th, where it was safely installed on April 26th, 2024, at 0320 hours. The longest arch span, weighing 2500 metric tonnes, was loaded on May 9th and successfully placed on May 15th, 2024, following thorough preparation and weather forecasting.

This revolutionary feat represents the first use of the float-over approach and leg mating devices in open seas for superstructure assembly in India. Pioneering approaches such as the two-body methodology, leg mating units, quick-lowering long stroke tidal jacks, rapid ballast systems, and strand jacks for sea-fastening have conquered weather obstacles and site constraints and represent a substantial development in construction and offshore projects in India.

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